1. Field of the Invention
The present invention relates to a photo-mask and a method of manufacturing semiconductor structures by using the same, and more particularly, to a photo-mask with forbidden pattern and a method of manufacturing a semiconductor structure by using the same.
2. Description of the Prior Art
To form fine patterns of semiconductor devices, etc., in the exposure process, phase shift masks, such as halftone phase shift mask, Levenson phase shift mask, etc. are used. The exposure with phase shift masks improves the exposure latitude, focal depth, etc. and is effective to form fine patterns. However, the phase shift masks are expensive, and recently, the mask (reticle) cost increase is a large serious problem.
As a countermeasure to the mask cost increase, it is proposed to use a multi-layer reticle (MLR) having multiple cells that used to define different physical layers and/or structures of an integrated circuit. Fabrication of multi-layer reticles requires preparation of datasets describing the reticles, fabrication of the reticles and inspection of the reticles. While the fabrication of multi-layer reticles can reduce mask fabrication costs compared to single-layer reticles where all cells are the same, the logistics requirements and inspections of multi-layer reticles can actually increase costs. Accordingly, there exists a need in the art to mitigate the deficiencies and limitations described hereinabove.